We painted the closet doors and wanted to change the doorknobs, and my wife requested a sewing button design ("like in Coraline"). We looked on the internets for an STL of such and it did not seem to already exist. I measured the old knob for approximate sizing, and then this was 5 minutes in OnShape. Size is about 40mm diameter by 30mm tall, with the area meeting the door 20mm in diameter, with a 4mm screw hole. (about 1.5" diameter by 1" tall, base is about 3/4" in diameter). Enjoy!